Your Question

My adult son has Renpenning syndrome. My daughter, who is healthy, gave birth to a son three years ago with the same. We recently learned that this condition is genetic. I would like to learn more about this condition. Are speech delays common in Renpenning syndrome? Do individuals with this condition require less sleep than average? Could my family, which has French Canadian heritage, be related to the Canadian family described by Renpenning in the 1960s? What can we expect?

Our Answer

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Renpenning syndrome is an inherited X-linked mental retardation condition which most often presents in males.[1] It is characterized by small head size (microcephaly), long narrow face, short stature, small testes, and intellectual deficit.[1][2][3] Renpenning syndrome is caused by mutations in the polyglutamine tract binding protein 1 gene (PQBP1).[1][2][3][4] Treatment is symptomatic and supportive.[5] In 2005, it was proposed that the various X-linked mental retardation syndromes with PQBP1 mutations be combined under the name of Renpenning syndrome.[1][3]

Last updated: 8/20/2009

What are the features of Renpenning syndrome?

The unifying features of Renpenning syndrome are mental retardation, microcephaly (small head size), short stature, and small testes.[1][2][3] The head tends to be narrow and tall with upslanting eye openings (palpebral fissures), abnormal nasal configuration, cupped ears, and short philtrum (the area between the nose and upper lip). The nose may appear long or bulb-like, with overhanging columella (the tissue that separates the nostrils). Less consistent manifestations include ocular colobomas, and anal anomalies.[3] The intellectual deficit is often severe and is present in 90 - 95% of cases. Less that 20% of cases have major malformations, the most common being heart defects and cleft palate.[1][2] Global developmental delays are present in all individuals, with significant delays in milestones such as walking and talking.[1][5]

Last updated: 8/20/2009

Is speech delay or absence a common feature of Renpenning syndrome?

Speech delay is a common finding in individuals with Renpenning syndrome. In fact, it is not uncommon for individuals with this condition to delay first speech until ages 3 or 4 years. In some cases, speech may never develop. In these cases, it is not unusual for the individuals to understand simple conversations.[5] Studies have also shown that some individuals with Renpenning syndrome have speech dyspraxia or developmental dyspraxia. These conditions may make it difficult for individuals with Renpenning syndrome to learn to speak or portray their thoughts into words.[6][7][8]

Last updated: 8/20/2009

My son did not sleep until he was three years old. My grandson is three and still requires very little sleep. Is there any association between sleep and Renpenning syndrome?

Our research did not uncover any particular association between sleep and Renpenning syndrome. We recommend that you speak with your grandson's physician if you have concerns regarding his sleeping patterns.

Renpenning syndrome is inherited in an X-linked recessive manner.[1][2][3] In most cases, the mutated gene is inherited from a carrier mother. Since males have only one X chromosome, a gene mutation on the X chromosome is fully expressed in males. Carrier females, with one normal X chromosome and one affected X chromosome, do not generally express the clinical signs of the condition. Female carriers, however, have a 50% chance of transmitting the altered gene to each son or daughter. A daughter inheriting the altered gene will be a carrier. A son inheriting an altered gene will have Renpenning syndrome.[9]

Last updated: 8/20/2009

How might Renpenning syndrome be treated?

There is no cure or standard treatment for Renpenning syndrome. Early educational intervention may be helpful for boys with this diagnosis.[5] Speech difficulties may also benefit from early intervention.[6]

Last updated: 8/20/2009

What is the prognosis for individuals with Renpenning syndrome?

Life threatening and other major health concerns have not been associated with Renpenning syndrome and life span does not appear to be shortened. Although some individuals may be able to hold down jobs and live independently as adults, others will require a more controlled group setting.[5]

Last updated: 8/20/2009

My family has some French Canadian heritage. Could the Renpenning syndrome in our family be traced back to the original family with Renpenning syndrome?

Although the first family described with Renpenning syndrome was from Canada, this condition is believed to be present in all racial and ethnic groups.[3] The Information Center cannot comment on your family's possible connection to the Canadian family described in the medical literature. However, if you wish to pursue this, a genetics professional may be able to assist you.